KR101690838B1 - Environment friendly resin composition having excellent impact strength and heat resistance - Google Patents

Abstract

The present invention relates to an eco-friendly resin composition containing plant-derived bioplastics, which is excellent in mechanical properties and high in heat distortion temperature (HDT) and comprises 100 parts by weight of a matrix resin containing 20 to 50% by weight of poly And 10 to 30 parts by weight of an? -Methylstyrene-based copolymer.

Description

[0001] The present invention relates to an environmentally friendly resin composition having excellent impact strength and heat resistance,

The present invention relates to an eco-friendly resin composition having excellent impact strength and heat resistance, and more particularly, to an eco-friendly resin composition containing plant-derived bioplastics having excellent mechanical properties and high heat distortion temperature (HDT) .

Polylactic acid (PLA) is one of the synthetic biodegradable resins and has recently been attracting much attention because it is a resin made from natural raw materials that can be regenerated. In terms of physical properties, strength and stiffness are excellent, Toughness, heat distortion temperature and gas barrier properties are poor, so there is a restriction in the product or area to which it is applied.

A polymer blend including a plant-derived regenerable bio-resin such as polylactic acid is referred to as a biobased blend. Currently, the polymer blend is developed for use as a packaging material, a fiber, an automobile interior material, and an electronic product , Desired processability, impact strength, heat resistance, and the like.

Although the polylactic acid has a low glass transition temperature (Tg = 56 ° C) in the case of the non-crystalline form, there is a limitation in the field of use, but the crystalline form has a high temperature resistance, Is also required to be developed.

BACKGROUND ART As a conventional technique, a polylactic acid, an ABS-based resin, and glycidyl methacrylate-styrene-acrylonitrile (hereinafter referred to as " Resin compositions containing a copolymer and poly (lactic acid), ABS resin, and methyl methacrylate-acrylonitrile-styrene copolymer have been developed to improve compatibility and improve physical properties such as impact strength to some extent , There was a limit in improving the heat resistance.

Therefore, there is still a demand for the development of environmentally friendly resin compositions containing polylactic acid as a main component and having sufficient biodegradation characteristics, mechanical properties and heat resistance.

In order to solve the problems of the prior art as described above, it is an object of the present invention to provide an eco-friendly resin composition containing plant-derived bioplastics with excellent mechanical properties and high heat distortion temperature.

Another object of the present invention is to provide a poly (lactic acid) -containing resin composition having high impact strength and heat resistance in order to produce biomass plastics for automobile interior materials conforming to environmentally friendly trends.

These and other objects of the present invention can be achieved by the present invention described below.

To achieve the above object, the eco-friendly resin composition according to the present invention comprises 100 parts by weight of a matrix resin containing 20 to 50% by weight of poly (lactic acid) and 10 to 30 parts by weight of an? -Methylstyrene-based copolymer.

The? -Methylstyrene-based copolymer may be a copolymer of? -Methylstyrene homopolymer or? -Methylstyrene and a monomer copolymerizable therewith.

The matrix resin may include an ABS-based copolymer.

The matrix resin may comprise a SAN-based copolymer.

The matrix resin may include a methacrylic acid alkyl ester polymer.

The matrix resin may contain 20 to 50% by weight of polylactic acid, 10 to 30% by weight of an ABS-based copolymer, 1 to 30% by weight of a SAN-based copolymer and 1 to 20% by weight of an alkyl methacrylate polymer.

The eco-friendly resin composition may further include an N-phenylmaleimide-based copolymer.

The N-phenylmaleimide-based copolymer may be contained in the eco-friendly resin composition in an amount within a range of 5 to 25 parts by weight based on 100 parts by weight of the matrix resin.

The eco-friendly resin composition may further contain a nucleating agent.

The nucleating agent may be a talc powder having an average particle size within a range of 1 to 10 mu m.

The nucleating agent may be contained in the eco-friendly resin composition in an amount within a range of 0.1 to 10 parts by weight based on 100 parts by weight of the matrix resin.

Wherein the environmentally friendly resin composition comprises 100 parts by weight of a matrix resin comprising 20 to 50% by weight of polylactic acid; 10 to 30 parts by weight of an? -methylstyrene-based copolymer; 5 to 25 parts by weight of an N-phenylmaleimide system; And 0.1 to 10 parts by weight of a nucleating agent.

According to the present invention, there is an effect of providing an eco-friendly resin composition containing plant-derived bioplastics with excellent mechanical properties, high heat distortion temperature, and the like.

Hereinafter, the present invention will be described in more detail.

The eco-friendly resin composition according to the present invention is characterized by comprising 100 parts by weight of a matrix resin containing 20 to 50% by weight of poly (lactic acid) and 10 to 30 parts by weight of an? -Methylstyrene-based copolymer. That is, the eco-friendly resin composition according to the present invention contains polylactic acid which is a regenerable biodegradable resin derived from plants as an essential component, and is excellent in mechanical properties due to mixing with other resins while improving environment- Which is one of the greenhouse gas components which are the cause of global warming, by containing polylactic acid, which is a plant-derived bio resin, in a large amount such as a resin composition having excellent processing characteristics, Friendly resin composition capable of appealing to consumers that it is a product.

The? -Methylstyrene copolymer is a copolymer of? -Methylstyrene homopolymer or? -Methylstyrene and a monomer copolymerizable therewith, preferably a copolymer of? -Methylstyrene and vinyl cyan monomer, more preferably? -Methyl styrene, vinyl cyan monomers and vinyl aromatic monomers. The vinyl cyan monomer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile. The vinyl cyan monomer may preferably be acrylonitrile. The vinyl aromatic monomer may be at least one selected from the group consisting of styrene and p-methylstyrene. The vinyl aromatic monomer may preferably be styrene. The? -Methylstyrene-based copolymer is more preferably a ternary copolymer comprising 40 to 80% by weight of? -Methylstyrene, 10 to 40% by weight of acrylonitrile and 1 to 20% by weight of styrene, It is preferably 5 to 15 g / 10 min under a load of 10 kg at a temperature of 220 캜 according to ASTM D1238. The α-methyl styrene type copolymer may have a mass average molecular weight of 50,000 to 250,000 g / mol and a glass transition temperature (Tg) of 110 to 130 ° C. or 115 to 125 ° C., specifically 120 ° C.

The matrix resin may contain 20 to 50% by weight of polylactic acid.

Here, the polylactic acid may be at least one selected from the group consisting of poly-L-lactic acid, poly-D-lactic acid and poly L, D-lactic acid. The polylactic acid preferably used in the present invention has a mass average molecular weight (Mw) of 50,000 to 250,000 g / mol, a polydispersity of 1.5 to 2, a glass transition temperature (Tg) of 50 to 60 ° C, 55 占 폚 and a melting point (Tm) of 150 占 폚 to 170 占 폚.

The content of the polylactic acid in the matrix resin should be within a range of 20 to 50% by weight based on the total weight of the matrix resin, so that the bioabase plastic authentication can be attained and it is preferable to exhibit excellent mechanical properties.

The matrix resin may include an ABS-based copolymer. The ABS-based copolymer is preferably a copolymer obtained by graft copolymerizing a vinyl aromatic monomer and a vinyl cyan monomer with a conjugated diene-based rubbery polymer, and may be obtained through emulsion polymerization. The ABS copolymer refers to an acrylonitrile-butadiene-styrene graft copolymer. Preferably, the ABS copolymer includes (i) 60 parts by weight of a large-diameter polybutadiene rubber latex having an average particle diameter of 2500 to 5000 ANGSTROM, Ii) from 15 to 30 parts by weight of a vinyl aromatic monomer, iii) from 10 to 25 parts by weight of a vinyl cyanide, iv) from 0.6 to 2.0 parts by weight of an emulsifier, v) from 0.2 to 1.0 part by weight of a molecular weight modifier, and from 0.05 to 0.5 parts by weight of a polymerization initiator By graft copolymerization. As a specific example, the large-diameter polybutadiene rubber latex of i) may be prepared by collectively administering 100 parts by weight of 1,3-butadiene, 1 to 4 parts by weight of an emulsifier, 0.1 to 0.5 parts by weight of a polymerization initiator, and 90 to 130 parts by weight of ion- For 12 hours to 50 to 65 ° C, and then 0.05 to 1.2 parts by weight of a molecular weight modifier is further administered in a batch and reacted at 55 to 70 ° C for 5 to 15 hours to prepare a small-diameter polybutadiene having an average particle size of 600 to 1,500 Å After 100 parts by weight of the prepared small-diameter polybutadiene rubber latex, 1.0 to 4.0 parts by weight of an aqueous acetic acid solution was gradually added (particle expanding step) with stirring for 1 hour to prepare a large-diameter polybutadiene rubber having an average particle diameter of 2500 to 5000 占Latex can be produced. As a specific example, the large-diameter rubber latex of i) is used in an amount of 50 to 100 parts by weight, usually 1 to 4 parts by weight, 0.2 to 1.5 parts by weight of a polymerization initiator, and 0.5 to 2 parts by weight of an electrolyte in 100 parts by weight of the total amount of the conjugated diene compound monomer 0.1 to 0.5 parts by weight of a molecular weight regulator and 75 to 100 parts by weight of ion exchange water are added to the mixture at a temperature of 65 to 75 ° C. for 4 to 15 hours and then the mixture of the remaining conjugated diene compound monomer and the molecular weight adjuster To 85 < 0 > C for 10 to 20 hours to prepare a large-diameter rubber latex having an average particle diameter of 2500 to 5000 angstroms.

15 to 30 parts by weight of a vinyl aromatic monomer, 10 to 25 parts by weight of a vinyl cyan compound, 0.6 to 2.0 parts by weight of an emulsifier, 0.2 to 1.0 part by weight of a molecular weight modifier, And 0.05 to 0.5 part by weight of a polymerization initiator are added and graft copolymerized at 40 to 80 ° C for 2 to 7 hours while 25 to 80 parts by weight of 100 parts by weight of total monomers used are administered at the initial stage of the reaction, When the reaction time is 30 to 90 minutes and the polymerization conversion rate is 40 to 90%, the remaining monomers may be administered in a batch or continuously, followed by further reaction for 1 hour and then the reaction is terminated. The latex may be obtained as an ABS-based copolymer in the form of a dry powder after the coagulation and drying process. For example, in the coagulation and drying process, distilled water is filled in the flocculation tank so that the total solids content is about 20 to 40%, 1 to 3 parts by weight of a 5 to 20% sulfuric acid aqueous solution is added as a flocculant, And continuously stirring the ABS copolymer latex under constant stirring, aging by raising the temperature to 70 to 90 캜, dewatering it, drying at 80 to 90 캜 to obtain a dry powdery form of an average particle size of 0.3 to 0.5 탆 To obtain an ABS-based copolymer.

The matrix resin may comprise a SAN-based copolymer. The SAN-based copolymer means a copolymer of a vinyl aromatic monomer and a vinyl cyan monomer. As the SAN-based copolymer, a resin prepared using conditions conventionally used in the art may be used, 40 to 90% by weight of the monomer and 10 to 60% by weight of the vinyl cyan monomer may be prepared by a continuous bulk polymerization method, more preferably 30 to 90% by weight of the styrene monomer and 10 to 70% by weight of the acrylonitrile monomer SAN copolymers prepared using the method of continuous mass polymerization in weight percent can be used.

The matrix resin may include a methacrylic acid alkyl ester polymer. The alkyl methacrylate polymer is preferably at least one polymer selected from the group consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, methyl ethacrylate, and ethyl ethacrylate, , And more preferably, methyl methacrylate may be used to improve impact resistance and processability. By adding such a methacrylic acid alkyl ester polymer to the thermoplastic resin composition, the compatibility of the resin composition can be improved, thereby improving not only the appearance quality but also the overall mechanical properties.

The alkyl methacrylate polymer preferably has a melt index of 3 to 20 g / 10 min under a load of 3.8 kg at a temperature of 230 DEG C in ASTM D1238.

The matrix resin preferably comprises 20 to 50% by weight of polylactic acid, 10 to 30% by weight of an ABS-based copolymer, 1 to 30% by weight of a SAN-based copolymer and 1 to 10% by weight of an alkyl methacrylate polymer .

The resin composition containing the ABS-based copolymer in an amount of 10 to 30% by weight in the composition of the matrix resin may have an appropriate impact strength as an automobile interior material, prevent excessive deterioration of heat resistance, It is preferable because it is possible to have paintability. In addition, the SAN-based copolymer is contained in an amount of 1 to 30% by weight in the composition of the matrix resin, but the mechanical properties such as impact strength and tensile strength of the resin composition obtained without deteriorating flowability and workability can be prevented Therefore, it is desirable. In addition, the alkyl methacrylate polymer is contained in an amount of 1 to 15% by weight to improve the compatibility of the resulting resin composition to have good appearance characteristics, and it is possible to improve impact strength, tensile strength, It can be used within a range in which mechanical properties such as strength are not weakened.

In the eco-friendly resin composition according to the present invention, the? -Methylstyrene-based copolymer is used in an amount within a range of 10 to 30 parts by weight based on 100 parts by weight of the matrix resin so as not to lower the compatibility of the composition, It is preferable because it is suitable for exhibiting mechanical properties.

The eco-friendly resin composition according to the present invention may further comprise an N-phenylmaleimide-based copolymer. The N-phenylmaleimide-based copolymer is a copolymer comprising 30 to 70% by weight of phenylmaleimide and 30 to 70% by weight of a vinyl aromatic monomer, wherein the weight average molecular weight is 50,000 to 20,000 g / mol, The temperature (Tg) is preferably 190 to 210 占 폚, specifically 200 占 폚.

The N-phenylmaleimide-based copolymer is contained in the eco-friendly resin composition in an amount within a range of 5 to 25 parts by weight based on 100 parts by weight of the matrix resin, particularly improving the heat resistance (heat distortion temperature) It is desirable to be able to reduce changes to other physical properties.

The eco-friendly resin composition may further contain a nucleating agent. The nucleating agent may be a talc powder having an average particle size within a range of 1 to 10 μm, and the nucleating agent may be included in the eco-friendly resin composition in an amount within a range of 0.1 to 10 parts by weight based on 100 parts by weight of the matrix resin The crystallization due to the formation of nuclei can be promoted and the heat resistance can be improved.

More preferably, the environmentally friendly resin composition comprises 100 parts by weight of a matrix resin containing 20 to 50% by weight of poly (lactic acid); 10 to 30 parts by weight of an? -methylstyrene-based copolymer; 5 to 25 parts by weight of an N-phenylmaleimide system; And 0.1 to 10 parts by weight of a nucleating agent.

The eco-friendly resin composition according to the present invention comprises the polylactic acid, and the α-methylstyrene type and / or the N-phenyl (meth) acrylate is added to the matrix resin containing the ABS copolymer and the SAN copolymer. A maleimide-based copolymer is added to improve the heat resistance and stiffness while maintaining the impact strength, and further the heat resistance can be further improved by adding a nucleating agent.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Changes and modifications may fall within the scope of the appended claims.

[Example]

Example 1

30 wt% of polylactic acid (PLA 4032D, product of Nature Works), 15 wt% of ABS copolymer (weight average molecular weight of 80,000), SAN copolymer (content of vinyl cyan monomer is 24 wt% (Molecular weight: 1,200,000) and 5% by weight of methacrylic acid ester polymer (melt index: 10 g / 10 min under a load of 3.8 kg at 230 DEG C in ASTM D1238) were mixed and kneaded to prepare a matrix resin.

The total amount of the matrix resin was changed to an α-methylstyrene-based copolymer (60% by weight of? -Methylstyrene, 30% by weight of acrylonitrile and 10% by weight of styrene and having a melt index according to ASTM D1238 of 220 占 폚 10 g / 10 min under a load of 10 kg at a temperature of 25 DEG C) were further mixed to obtain an eco-friendly resin composition according to the present invention.

The average particle diameter, distribution, tensile strength, flexural modulus, impact strength and heat distortion temperature of the obtained environmentally friendly resin composition were measured respectively by the following methods, and the results are shown in Table 1 below.

* Average particle size and distribution - The dynamic laser light skating method was performed using Nicomp 370HPL.

Tensile strength (unit: kgf / cm2) - Measured at a speed of 5 cm / min by ASTM D638 test method.

Flexural Modulus (Unit: kgf / cm2) - Measured at a speed of 1.5 cm / min by the ASTM D790 test method.

Impact strength (unit: kgf / cm) - Measured on 1/8 inch notched specimens by ASTM D256 test method.

* Thermal deformation temperature (unit: 占 폚) - Measured by ASTM D648 test method.

Examples 2 to 7

The procedure of Example 1 was repeated, except that the components and the contents of the following Table 1 were used.

Comparative Examples 1 to 6

The results are shown in Table 2, except that the components and contents in Table 2 were used.

division Example One 2 3 4 5 6 7


Furtherance
(wt%) Poly lactic acid 30 30 30 35 30 30 40 ABS-based copolymer 15 20 25 20 20 20 20 SAN-based copolymer 25 23 20 10 10 10 10 Methacrylic acid methyl ester polymer 5 5 5 5 5 5 5 N-phenylmaleimide - - 10 20 15 14 13 alpha -methylstyrene-based copolymer 25 22 10 10 20 20 12 Nucleating agent - - - - - One -


Properties The tensile strength
(Kgf / cm2) 580 570 540 545 547 550 560 Flexural modulus
(Kgf / cm2) 26000 25000 23500 23400 23400 23600 24500 Impact strength
(Kgf / cm) 8 12 16 10 15 13 11 Heat distortion temperature
(° C) 97 95 98 102 100 102 96 N-phenylmaleimide = N-phenylmaleimide-based polymer

division Comparative Example One 2 3 4 5 6

Furtherance
(%) Poly lactic acid 30 30 30 30 30 40 ABS-based copolymer 10 20 30 30 30 30 SAN-based copolymer 60 50 40 35 30 20 Methacrylic acid methyl ester polymer - - - 5 5 5 Glass fiber - - - - 5 5


Properties The tensile strength
(Kgf / cm2) 380 360 350 410 530 535 Flexural modulus
(Kgf / cm2) 18500 18000 17000 19000 25000 24000 Impact strength
(Kgf / cm) 10 20 35 50 5 3 Heat distortion temperature
(° C) 75 72 68 68 95 85

As shown in Table 1 and Table 2, when the amount of the? -Methylstyrene copolymer and / or the N-phenylmaleimide-based copolymer is increased according to the present invention, the heat distortion temperature is increased to improve the heat resistance In particular, it is possible to adjust the tensile strength and the impact strength to be increased in accordance with the increase of the content of the ABS-based copolymer. In general, the flexural modulus can be adjusted to a substantially constant level As shown in Fig. In particular, it was confirmed that even if the content of the N-phenylmaleimide-based copolymer is lowered by an additional amount of the nucleating agent in addition to the nucleating agent, the heat distortion temperature can be increased and the heat resistance can be improved.

Claims (12)

100 parts by weight of a matrix resin comprising 20 to 50% by weight of polylactic acid, 10 to 30% by weight of an ABS copolymer, 1 to 30% by weight of a SAN copolymer and 1 to 20% by weight of an alkyl methacrylate polymer, 10 to 30 parts by weight of a methylstyrene-based copolymer and 5 to 25 parts by weight of an N-phenylmaleimide-based copolymer,
Wherein the polylactic acid has a weight average molecular weight of 50,000 to 250,000 g / mol, a polydispersity of 1.5 to 2 and a glass transition temperature (Tg) of 50 to 60 DEG C measured by a dynamic laser light skating method using Nicomp 370HPL,
The alkyl methacrylate polymer had a melt index of 3 to 20 g / 10 min at 230 캜 under a load of 3.8 kg in accordance with ASTM D1238,
The α-methylstyrene type copolymer has a mass average molecular weight of 50,000 to 250,000 g / mol, a melt index of 5 to 15 g / 10 min and a glass transition temperature (Tg) of 110 to 130 ° C. under a load of 10 kg at 220 ° C. according to ASTM D1238 40 to 80% by weight of? -methylstyrene, 10 to 40% by weight of acrylonitrile and 1 to 20% by weight of styrene,
Wherein the N-phenylmaleimide-based copolymer has a weight average molecular weight of 50,000 to 200,000 g / mol and a glass transition temperature (Tg) of 190 to 210 ° C. delete delete delete delete delete delete delete The method according to claim 1,
Wherein the eco-friendly resin composition further comprises a nucleating agent. 10. The method of claim 9,
Wherein the nuclear material is talc powder having an average particle diameter within a range of 1 to 10 mu m. 10. The method of claim 9,
Wherein the nucleating agent is included in the eco-friendly resin composition in an amount within a range of 0.1 to 10 parts by weight based on 100 parts by weight of the matrix resin. 100 parts by weight of a matrix resin comprising 20 to 50% by weight of polylactic acid, 10 to 30% by weight of an ABS-based copolymer, 1 to 30% by weight of a SAN-based copolymer and 1 to 20% by weight of an alkyl methacrylate polymer; 10 to 30 parts by weight of an? -methylstyrene-based copolymer; 5 to 25 parts by weight of an N-phenylmaleimide-based copolymer; And 0.1 to 10 parts by weight of a nucleating agent,
Wherein the polylactic acid has a weight average molecular weight of 50,000 to 250,000 g / mol, a polydispersity of 1.5 to 2 and a glass transition temperature (Tg) of 50 to 60 DEG C measured by a dynamic laser light skating method using Nicomp 370HPL,
The alkyl methacrylate polymer had a melt index of 3 to 20 g / 10 min at 230 캜 under a load of 3.8 kg in accordance with ASTM D1238,
The α-methylstyrene type copolymer has a mass average molecular weight of 50,000 to 250,000 g / mol, a melt index of 5 to 15 g / 10 min and a glass transition temperature (Tg) of 110 to 130 ° C. under a load of 10 kg at 220 ° C. according to ASTM D1238 40 to 80% by weight of? -methylstyrene, 10 to 40% by weight of acrylonitrile and 1 to 20% by weight of styrene,
Wherein the N-phenylmaleimide-based copolymer has a weight average molecular weight of 50,000 to 200,000 g / mol and a glass transition temperature (Tg) of 190 to 210 ° C.